Efficiency: Release builds by default, only the visible island screen is built, character at 30 fps, adaptive mouse polling (60/30/10 Hz), hex colours parsed once

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

NotchBuddy/Sources/App/IslandRootView.swift

@@ -498,7 +498,9 @@ struct IslandContentView: View {
                 .animation(.easeInOut(duration: 0.2), value: state.view == .confused)
 
             ZStack {
-                ForEach(IslandView.allCases, id: \.self) { v in
+                // Only the visible screen is built (plus the chat, to keep its draft and
+                // scroll): hidden screens used to keep their animations and timers running.
+                ForEach(IslandView.allCases.filter { $0 == state.view || $0 == .prompt }, id: \.self) { v in
                     let active = state.view == v
                     // Views that fill available height instead of the fixed 98pt content frame:
                     // chat (prompt) is always flexible; mail is flexible only when active so
@@ -514,6 +516,7 @@ struct IslandContentView: View {
                         .opacity(active ? 1 : 0)
                         .scaleEffect(active ? 1 : 0.97)
                         .allowsHitTesting(active)
+                        .transition(.opacity)
                         .animation(anim, value: state.view)
                 }
             }